Make this database easier to trust and operate

I want this PostgreSQL database to become easier to maintain, faster where it matters, less expensive to operate, and more trustworthy.

Study how the database actually works today, including its schema, important relationships, data sources, reads, writes, background jobs, migrations and consumers. Use the real database state, repository and operational evidence rather than relying on documentation alone.

Find the few underlying problems responsible for the greatest amount of unnecessary complexity, repeated work, data-quality risk and operational expense.

I care especially about correctness of the underlying data, efficient and reliable writes, duplicated logic, unnecessary database objects, historical accuracy, and changes that make future development easier for coding agents.

Rank the opportunities by actual impact. Distinguish demonstrated problems from theoretical concerns, and don't recommend a redesign just because an approach is unconventional.

Make recommendations that simplify the existing system rather than introduce more infrastructure or recurring processes. Reuse evidence already gathered, investigate only what's needed to support a decision, and group related findings around their shared cause.

Use read-only investigation initially. Don't modify production data, schemas or infrastructure. Give me the strongest findings, what proves them, and the smallest changes that would produce meaningful improvements.